You can't get away from having to reason about NULL in SQL even if you remove all NULLs from the database. You can still get NULLs at query time, and they'll h

You can't get away from having to reason about NULL in SQL even if you remove all NULLs from the database. You can still get NULLs at query time, and they'll have semantically valid meanings in views and subqueries.